1. Field of the Invention
This invention relates to a process and apparatus for applying and compacting castable material in a step-like arrangement of strips on a sloped surface and more particularly to a process and apparatus for paving the sloped surface with strips having a preselected thickness and lateral dimension with a preselected degree of compaction.
2. Description of the Prior Art
Earthen structures for holding back or containing a body of water as for example in the instance of canals, dikes, coastal breakers, cooling ponds, diversion islands and the like are subject to erosion by the generation of waves within the body of water. The earthen structure generally consists of sloping walls having a smooth surface which presents little or no resistance to waves. Consequently, under high wind conditions the wave problem can increase to the point where water is directed over the top of the earthen structure and directed upon the foundation thereof. If this condition is allowed to continue eventual erosion of the foundation will occur, weakening the earthen structure until it is no longer capable of holding back the body of water. The erosion problem is magnified by the fact that the smooth sloped surface of the earthen structure presents little or no resistance to the waves. Therefore, in order to prevent erosion of the earthen structure it is known to break up the wave action generated within the body of water by constructing a step-like surface on the slope of the earthen structure. U.S. Pat. No. 3,966,343 discloses a paving machine that covers a sloping surface of the earthen structure of a cooling pond with a series of step-like strips that extend longitudinally upon the sloped surface. The strips are cast in a continuous process and are constructed of a castable material that includes an admixture of soil and cement. It is also known to employ other methods of constructing strips or breakers on a sloped surface that require the use of forms which must be constructed before the castable material is poured. It has also been suggested to erect step-like breakers by laying precast breakers in strips upon the sloped surface. However, these methods require a considerable expenditure of effort and time in their construction.
While it has been suggested to construct breakers on a sloped surface by a continuous casting process that eliminates the use of forms, there is need for an apparatus for continuously casting strips in which each strip has a preselected thickness and extends at a preselected lateral dimension outwardly from the sloped surface. Furthermore, it is critical in a continuous casting process that the strips be compacted to a preselected degree of compaction in order to resist the forces of erosion.